Prefabricated House Pros and Cons

Hello,

We have read and watched a lot over the past few days, but now we are even more confused. By now, we have not even the slightest idea what might be right for us.

That is "normal" at first, since you are entering unfamiliar territory for you; it will get better with every goal-oriented conversation, don't worry.

Where do you want to build?

Kind regards

Where do you want to build?

Hello!

We want to build in Lower Bavaria, around Landshut/Dingolfing.

... then there is still the screed and it requires drying times with both variants.

... but only if both groups of providers use the same wet screed, you forego the interior plaster, and believe that the building is consistently protected from rain during the shell construction phase.

The equalization moisture level you mentioned is therefore reached much faster, especially if the building envelope is additionally provided with a breathable facade/coating. The 4 years you mentioned may have been a valid statement in earlier times, but today this number has been significantly reduced.

This fact I have pointed out is based on the statement of Prof. Dr. Karl Gertis (at that time still head of the Fraunhofer Institute for Building Physics), which certainly dates back several years. Incidentally, he once spoke to over 600 architects, civil engineers, and contractors on the topic "The myth of walls breathing" at an event organized by a leading manufacturer of small-format wall elements in the Dortmund area.
However, at that time glued bedding joints and thermal insulation composite systems (of course also and especially in solid construction) were already being used.

The prefab house industry uses synthetic resin plasters (ETICS), which makes the building body take longer to get rid of excess moisture => to put it bluntly, living in a foil. It is not without reason that the installation of a controlled ventilation system is recommended to avoid not only mold but also this "sauna feeling."

Here cause and effect as well as a resulting "compulsion" to install a ventilation system are probably not described correctly.

As I already said, in the end the gut decides between the various options.

Certainly countless far-reaching decisions are made daily with a 70-80% contribution from the gut level, but this ratio between head and gut level should probably be reversed especially when choosing a residential building concept!

Hello,

We want to build in Lower Bavaria, around Landshut/Dingolfing.

If you want to get independent advice beforehand – before you enter into discussions with house sellers – I can warmly recommend a meeting with the Energy Agency. I have had good experiences with this agency here in the Rhineland, not only regarding the energy aspect; they also provide practical tips on building and renovating.

Kind regards

Hello KPS,

... but only if both supplier groups use the same wet screed…

I am very old-fashioned in that I always compare apples to apples

...This circumstance I pointed out is based on the statement of Prof. Dr. Karl Gertis (then head of the Fraunhofer Institute for Building Physics)…"The myth of walls breathing"…

Caught - of course it is not correct to speak of walls "breathing," because it leads to misunderstandings; Pettenkofer has slipped into my vocabulary What was meant and still is: walls and other building components (here the exterior plaster) should be as "diffusion-capable, hygroscopic, and sorption-capable"** as possible and thus contribute to regulating indoor air humidity, absorbing odors and air pollutants, and keeping buildings dry.

... Here cause and effect as well as a resulting "compulsion" to install a ventilation system are probably not described correctly.

Certainly not as correctly as you would like as a mathematician, but in a way that laypeople understand (not without reason I put two asterisks below and explained the uncommon terms from the last paragraph). I have made it a habit to reduce things to the point so that understanding arises quickly, without demanding building physics knowledge from my counterpart.

Surely countless far-reaching decisions are made daily with a share of 70-80% from the gut level, but this ratio between the head and gut level should be rather the opposite when choosing a residential building concept!

I have been working with people for over 25 years now, for 14 years I have been working as a salesperson for solidly built single-family homes and have given up discussing this subjunctive. I try to do my job as well as possible and offer honest performance; also after signing the contract. For a vanishingly small number of builders—measured by my appointments in relation to the closing—this job view is exactly right; for the vast majority of contacts, it still applies that they believe want to believe what the cheapest provider tells them.


** Very well, moisture can be transported outward through a diffusion-open wall. The vapor transmission of a wall with a total sd-value of 5 m is about 4 g per hour per m²; i.e. for a normal single-family house (approx. 150 m² exterior wall area) about 14.4 liters. A diffusion-open wall thus ensures that both relative humidity and the surface temperature of the inside of the exterior walls provide a comfortable climate.


“Water vapor diffusion equivalent air layer thickness” (abbreviated: sd-value)

Building physics: all materials have the ability to slow down the gas transmission (= diffusion)


Best regards

Hello,

If you want to get independent advice in advance - before you enter into talks with house sellers - I can highly recommend a conversation with the Energy Agency. I have had good experiences with this agency here in the Rhineland, not only regarding the energy aspect; they also provide practical tips on building and renovating.

Kind regards

Thank you very much for the link! Since we now have 3 weeks of vacation ahead, we will arrange an appointment for the consultation!